Many vehicles today are equipped with receiver-type trailer hitches. These types of trailer hitches typically are a square tube, normally 1¼ or 2 inches internal height and width, attached to the undercarriage of the vehicle. A second tube acts as a shank and includes outer dimensions slightly smaller than the internal dimensions of the receiver tube is slidable within the receiver tube. The shank tube is connected to the receiver tube by a pin inserted through the two tubes and locked or clipped to prevent relative movement between the two tubes.
The shank tube may include a standard ball-mount for engaging with the hitch of a trailer or other wheeled vehicle. Another popular use for receiver hitches is the use as a coupling device for installing equipment racks onto the vehicle. Bicycle carrier racks, ski carriers, storage boxes and other types of carriers have been designed to use the above-described second tube to engage within a receiver hitch tube. This provides a universal system that allows a vehicle user to be able to use various trailers and carriers with a single coupling system.
A particular problem with the use of these receiver coupling systems is the clearance between the internal dimensions of the receiver tube and the external dimensions of the shank tube. These tubes by necessity must have sufficient clearance to be able to be easily telescoped together. However, this clearance between the two tubes causes relative movement between the two tubes. The shank tube tends to rattle or chatter within the receiver tube. This rattle or chatter is at best an annoyance and at worst can distract the driver or cause damage to the trailer or the carrier.
There have been a number of attempts to solve this problem in the past. These attempts all required the use of specially designed receivers, shanks, or accessories in order to reduce the rattle between the receiver and shank. Examples of these prior attempts are disclosed in U.S. Pat. No. 5,423,566; U.S. Pat. No. 5,593,172; U.S. Pat. No. 5,735,539; U.S. Pat. No. 5,879,102; U.S. Pat. No. 5,988,667; U.S. Pat. No. 6,010,049; U.S. Pat. No. 6,010,143; U.S. Pat. No. 6,010,144; and U.S. Pat. No. 6,105,989. These prior devices either require specially designed receivers and shanks or use extraneous mounting devices to minimize the rattle between the receiver and the shank.
Another existing system for minimizing the movement and rattle between a receiver tube and shank tube is the Silent Hitch Pin by Let's Go Aero, Inc. as described in U.S. Pat. Nos. 6,409,203; 6,609,725; and 6,945,550 and in U.S. Published Application 20050236811. This system uses a resilient nut mounted within the receiver tube. The hitch pin includes a threaded portion which engages the resilient nut to secure the shank tube against the receiver tube to minimize the relative movement and rattle between the receiver tube and shank tube. These systems work well but often require tools to tighten the hitch pin with the resilient nut.
There presently is a need for a device that will minimize the rattle between the receiver tube and the shank tube. There is a further need for a device that can be used with most of the existing receiver systems presently in use. There is also a need for a device that can be securely tightened without the need of tools.